/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package websocket.drawboard;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.geom.Arc2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;

/**
 * A message that represents a drawing action. Note that we use primitive types instead of Point, Color etc. to reduce object allocation.<br>
 * <br>
 *
 * TODO: But a Color objects needs to be created anyway for drawing this onto a Graphics2D object, so this probably does not save much.
 */
public final class DrawMessage
{
    
    private int type;
    
    private byte colorR, colorG, colorB, colorA;
    
    private double thickness;
    
    private double x1, y1, x2, y2;
    
    /**
     * The type.
     *
     * @return 1: Brush<br>
     *         2: Line<br>
     *         3: Rectangle<br>
     *         4: Ellipse
     */
    public int getType()
    {
        return type;
    }
    
    public void setType(int type)
    {
        this.type = type;
    }
    
    public double getThickness()
    {
        return thickness;
    }
    
    public void setThickness(double thickness)
    {
        this.thickness = thickness;
    }
    
    public byte getColorR()
    {
        return colorR;
    }
    
    public void setColorR(byte colorR)
    {
        this.colorR = colorR;
    }
    
    public byte getColorG()
    {
        return colorG;
    }
    
    public void setColorG(byte colorG)
    {
        this.colorG = colorG;
    }
    
    public byte getColorB()
    {
        return colorB;
    }
    
    public void setColorB(byte colorB)
    {
        this.colorB = colorB;
    }
    
    public byte getColorA()
    {
        return colorA;
    }
    
    public void setColorA(byte colorA)
    {
        this.colorA = colorA;
    }
    
    public double getX1()
    {
        return x1;
    }
    
    public void setX1(double x1)
    {
        this.x1 = x1;
    }
    
    public double getX2()
    {
        return x2;
    }
    
    public void setX2(double x2)
    {
        this.x2 = x2;
    }
    
    public double getY1()
    {
        return y1;
    }
    
    public void setY1(double y1)
    {
        this.y1 = y1;
    }
    
    public double getY2()
    {
        return y2;
    }
    
    public void setY2(double y2)
    {
        this.y2 = y2;
    }
    
    public DrawMessage(int type, byte colorR, byte colorG, byte colorB, byte colorA, double thickness, double x1, double x2, double y1, double y2)
    {
        
        this.type = type;
        this.colorR = colorR;
        this.colorG = colorG;
        this.colorB = colorB;
        this.colorA = colorA;
        this.thickness = thickness;
        this.x1 = x1;
        this.x2 = x2;
        this.y1 = y1;
        this.y2 = y2;
    }
    
    /**
     * Draws this DrawMessage onto the given Graphics2D.
     *
     * @param g The target for the DrawMessage
     */
    public void draw(Graphics2D g)
    {
        
        g.setStroke(new BasicStroke((float)thickness, BasicStroke.CAP_ROUND, BasicStroke.JOIN_MITER));
        g.setColor(new Color(colorR & 0xFF, colorG & 0xFF, colorB & 0xFF, colorA & 0xFF));
        
        if (x1 == x2 && y1 == y2)
        {
            // Always draw as arc to meet the behavior in the HTML5 Canvas.
            Arc2D arc = new Arc2D.Double(x1, y1, 0, 0, 0d, 360d, Arc2D.OPEN);
            g.draw(arc);
            
        }
        else if (type == 1 || type == 2)
        {
            // Draw a line.
            Line2D line = new Line2D.Double(x1, y1, x2, y2);
            g.draw(line);
            
        }
        else if (type == 3 || type == 4)
        {
            double x1 = this.x1, x2 = this.x2, y1 = this.y1, y2 = this.y2;
            if (x1 > x2)
            {
                x1 = this.x2;
                x2 = this.x1;
            }
            if (y1 > y2)
            {
                y1 = this.y2;
                y2 = this.y1;
            }
            
            // TODO: If (x1 == x2 || y1 == y2) draw as line.
            
            if (type == 3)
            {
                // Draw a rectangle.
                Rectangle2D rect = new Rectangle2D.Double(x1, y1, x2 - x1, y2 - y1);
                g.draw(rect);
                
            }
            else if (type == 4)
            {
                // Draw an ellipse.
                Arc2D arc = new Arc2D.Double(x1, y1, x2 - x1, y2 - y1, 0d, 360d, Arc2D.OPEN);
                g.draw(arc);
                
            }
        }
    }
    
    /**
     * Converts this message into a String representation that can be sent over WebSocket.<br>
     * Since a DrawMessage consists only of numbers, we concatenate those numbers with a ",".
     */
    @Override
    public String toString()
    {
        
        return type + "," + (colorR & 0xFF) + "," + (colorG & 0xFF) + "," + (colorB & 0xFF) + "," + (colorA & 0xFF) + "," + thickness + "," + x1 + "," + y1 + "," + x2 + "," + y2;
    }
    
    public static DrawMessage parseFromString(String str)
        throws ParseException
    {
        
        int type;
        byte[] colors = new byte[4];
        double thickness;
        double[] coords = new double[4];
        
        try
        {
            String[] elements = str.split(",");
            
            type = Integer.parseInt(elements[0]);
            if (!(type >= 1 && type <= 4))
            {
                throw new ParseException("Invalid type: " + type);
            }
            
            for (int i = 0; i < colors.length; i++)
            {
                colors[i] = (byte)Integer.parseInt(elements[1 + i]);
            }
            
            thickness = Double.parseDouble(elements[5]);
            if (Double.isNaN(thickness) || thickness < 0 || thickness > 100)
            {
                throw new ParseException("Invalid thickness: " + thickness);
            }
            
            for (int i = 0; i < coords.length; i++)
            {
                coords[i] = Double.parseDouble(elements[6 + i]);
                if (Double.isNaN(coords[i]))
                {
                    throw new ParseException("Invalid coordinate: " + coords[i]);
                }
            }
            
        }
        catch (RuntimeException ex)
        {
            throw new ParseException(ex);
        }
        
        DrawMessage m = new DrawMessage(type, colors[0], colors[1], colors[2], colors[3], thickness, coords[0], coords[2], coords[1], coords[3]);
        
        return m;
    }
    
    public static class ParseException extends Exception
    {
        private static final long serialVersionUID = -6651972769789842960L;
        
        public ParseException(Throwable root)
        {
            super(root);
        }
        
        public ParseException(String message)
        {
            super(message);
        }
    }
    
}
